The present invention relates to mechanized sweepers of the type used for sweeping paved areas, parking areas, and roads and, more particularly, to such sweepers of the type using a hydraulic motor to drive the primary fan and one or more additional hydraulic motors to drive various auxiliary devices, such as gutter broom(s), associated with operation of the sweeper.
Various types of mechanized wheeled vehicles are known for use in sweeping paved surfaces. For example, truck-mounted sweepers are known for sweeping highway and roadway surfaces while other types of sweepers are more suited for sweeping paved areas typically used for parking motor vehicles. In general, pavement sweepers can include a standard truck chassis and a sweeper unit that is mounted to the truck chassis. In most cases, the sweeper unit includes a motor-driven fan, a pick-up head, and a debris-separation hopper. The fan creates a recirculating air flow with the air flow passing from the hopper to and through the pick-up head and back into the hopper where dust, particles, and other debris are removed from the air flow by known separation techniques. In early versions of some types of sweepers, the fan wheel was driven by a drive-shaft connected through a power take-off to the truck engine. In many contemporary sweeper designs, the fan wheel is driven by an auxiliary internal combustion motor that is independent of the truck engine, and, in other contemporary sweeper designs, the fan wheel is driven by a hydraulic motor that receives a flow of hydraulic fluid from a hydraulic pump driven by the truck engine.
In those sweeper designs that use a hydraulic motor to drive the fan wheel, an auxiliary pump is often mounted adjacent to the shaft connecting the fan wheel to its drive motor. The auxiliary pump is typically connected to and driven by the fan shaft through a pulley and belt(s) arrangement so that rotation of the fan shaft will also drive the auxiliary pump. The auxiliary pump then provides a flow of fluid for driving the gutter broom motor(s) as required and other hydraulic accessories, including one or more hydraulic cylinders. This system is adequate for its intended purpose, however, the auxiliary belt-driven pump adds mechanical complexity and cost to the construction of the machine.